Most of the existing brewing mechanisms for coffee machines have complicated structures and too many assemblies, making it hard to operate and inconvenient to use. For example, a commercially available brewing mechanism inside which the capsule can fall off automatically comprises a handle, a front cover assembly and a rear cover assembly, wherein the front cover assembly or the rear cover assembly is connected with a connecting rod by a rotatable handle, which makes the front cover assembly move forward and tightly press the rear cover assembly so as to fulfill a sealed engagement between them, and also makes the front cover assembly move backward and hook out the capsule which would thereafter fall into the capsule receiving section. The characteristic of the structure is that guiding slots are provided on the left and right sides of the front cover assembly, and a fixing shaft is provided on the front end of the front cover assembly for its connection with the connecting rod. The connecting rod is fixed on a frame fixing point and connected with the handle. The front cover assembly and the rear cover assembly together form a rocker arm structure which can move straightly. The opening and closing of the front cover assembly of the brewing mechanisms needs to be operated manually and there are too many assemblies and too complicated structure in this mechanism.